1. Field of the Invention
The invention relates to the field of semiconductor memories.
2. Prior Art
Static memories are widely used in the semiconductor industry. For example, these memories are often used for cache memories. Typically, these memories are fabricated from a plurality of bistable circuits (flip-flops) each forming a cell for storing one bit of data. In the memory array bit lines are precharged for reading data from the cells; these bit lines are also used during writing by driving the lines to the desired state as determined by the incoming data.
Dual port static memory cells are also known in the prior art. An example of one such cell is shown in U.S. Pat. No. 4,823,314.
As can be seen, the present invention provides a dual port static memory where a read-modify-write operation can occur in one memory cycle. The memory also includes a circuit for resolving conflicting write data when one cell is accessed at both its ports.